This invention relates generally to improvements to photoplotter equipment, and deals more particularly with improvements made to the media lifting shoe of a material handling apparatus as well as relating to improvements in curved form cassettes and associated devices for uncovering an otherwise closed supply cassette in the light-tight confines of a material handler, and further deals with automatically covering a collecting cassette once imaged media are discharged into it while still maintained within the light impervious confines of the handling unit.
In co-pending U.S. application Ser. No. 08/071,567, discussion is made of handling media of a flexible type, e.g. a photosensitive film, a photosensitive plate, or the like having a relatively thin thickness of approximately on the order of about 0.007 inches, so as to allow the media sheets to conform to a generally partially cylindrical support surface in a plotter. Such curved support surfaces are found in drum-type plotters, such as disclosed in co-pending U.S. patent application Ser. No. 07/839,398 now U.S. Pat. No. 5,276,465, entitled PLOTTER DRUM AND METHODS OF FABRICATION AND ALIGNMENT THEREFORE, filed on Feb. 20, 1992, in the name of Alan Menard et al. involved using a scanning device which images in raster format a media sheet supported on the drum below it. As such, it should be understood that the need to move media onto such a curved support surface involves the handling of media sheets in a curved form so that the media can substantially automatically assume the configuration of the support surface once transported to the support surface during the loading process. Therefore, lifting of the media sheet from a supply of such media to the support surface must be done with this in mind. To these ends, the media is thus maintained in curved form even while stacked in a supply so that individual sheets can be located on the photoplotter drum in a curved condition. In addition, the media sheets involved are photosensitive, in some cases reactant to room light, and therefore must be contained in a light-tight environment even when stored as a supply as well as when being imaged in the photoplotter. Thus, it is important that the means by which media sheets are stored in a light-tight supply container and by which the container is subsequently uncovered via an uncovering process, always protect the light-tight integrity of the container.
Accordingly, it is an object of the present invention to provide an improved media handler of the type which is connectable to pre-existing photoplotter structure and which handler is capable of advancing media sheets from a supply of such media located within the handler to a drum plotter and return the imaged media to the handler without exposure to room light.
It is yet a further object of the invention to provide an improved media handling device of the type wherein media having a flexible form is supported to conform it to the general configuration of the support surface onto which it will ultimately be placed by engaging it with a shoe which is likewise flexible allowing the shoe to conform to the given shape of the media as supported on a support surface.
It is yet a further object of the invention to provide a light-tight media handling system wherein media cassettes are adapted for light-tight storage either as collecting cassettes or supply cassettes, and are capable of being respectively readily covered and uncovered within the handler without hazard of exposure to room light.
Other objects and aspects of the invention will become more readily apparent by the below specification and appended claims.